Hi,
I have a data of patients on which i have to apply Chi square test.
The data is in the following format:-

S NO. NO. OF DAYS ON INCIDENCE OF
PATIENT IS ON VENTILATION INFECTION
1. 9 INFECTED
2. 11 INFECTED
3. 4 NOT INFECTED
4. 8 INFECTED
5. 6 NOT INFECTED
6. 13 INFECTED
7. 12 INFECTED
8. 4 NOT INFECTED

The probability is higher in case of patient being on ventilation for a
longer period of time.
I want to apply Chi square test on the above data.If some body
can help me out.
Thanks in advance

Regards
Rajeev